Sources at Whitehall recently stated that the Government is poised to approve the provision of non-invasive prenatal testing (NIPT) for Down syndrome and other serious chromosomal disorders to all high risk women on the NHS. This has happened against a backdrop of extensive debate. Some campaigners fear that the implementation of NIPT on the NHS will lead to an increase of terminations of babies with Down syndrome. I would like to address those concerns, and offer up the perspective of a medical practitioner on the ongoing debate.
Women who don't want testing will continue not to have it:
I can appreciate concerns from campaigning groups about better sensitivity of prenatal screening leading to more diagnoses and terminations of Down syndrome babies. The wider context of screening, however, should be considered. Arguably, women who don't want testing will continue not to have it, and those who want a test will be relieved to be offered an option which is safer, better, faster and carries no risk of miscarriage, unlike the existing CVS or amniocentesis tests.
Learning information early gives families time to prepare:
Not all pregnant women terminate pregnancy when it is found their child has a syndrome like Down's - a recognisable number of women choose to continue pregnancy and are supported in this choice. Learning this information early gives them and their families time to prepare for having a child with Down syndrome, and also allows doctors to make sure that the baby is looked after when it is born.
Due to the lack of accuracy of the current combined screening, not all women who receive a high risk result will actually have an affected pregnancy:
Currently, screening for Down's is offered to all pregnant women on the NHS through either the combined test (ultrasound and blood test) or quadruple test (blood tests only) depending on the stage of pregnancy. Screening provides an estimate of risk - what is the likelihood of carrying a baby with Down Syndrome. All women deemed at higher risk on these screening tests are offered an invasive diagnostic test (amniocentesis or CVS) . However, at best, the combined and quadruple tests are 75-90% sensitive, meaning that up to 25% of all Down's babies can be missed. Also, due to the lack of accuracy, most women who receive a high risk screening result will not actually have an affected pregnancy.
The current price for reassurance is the risk of miscarriage:
Faced with a higher risk result, the decision whether or not to undergo invasive testing can be agonising for expectant parents. In around 8 out of 9 cases, the result from the diagnostic test will be normal. However, the price for that reassurance is the small risk of miscarriage and the associated stress, discomfort and anxiety of the invasive procedure.
Like most healthcare providers, I welcome the move to offer the NIPT screening test to NHS patients:
In our hospital, we offer the IONA test, the first NIPT screening test to be CE marked for quality, but women still have to pay for it. Like most healthcare providers, I welcome the move to offer the NIPT screening test to NHS patients. With NIPT we now have a test that is over 99% accurate in the detection of pregnancies affected with Down syndrome, and requires only a blood sample from a pregnant woman. With the enhanced accuracy of this type of testing, a low-risk result with IONA means it is highly unlikely that the baby will have Down Syndrome. However, it is important to remember that NIPT is a screening, not a diagnostic test; it is accurate, but not 100% accurate, so any women with a higher risk result following this new test will still be offered invasive testing.
NIPT offers real benefits to my patients:
This development represents a paradigm shift in prenatal care and NIPT offers real benefits to the women I see at the John Radcliffe Hospital. It is not only the most accurate form of chromosomal screening, it is also safe and simple, which is great from a practitioner's perspective, and very reassuring to pregnant women - both those at high risk and those just wanting the best test.
I hope that the Government continues to move forward with the processes to offer NIPT on the NHS to all high risk women, and that those who oppose it start to see the real benefits which it can offer to women across the UK.
Dr Brenda Kelly has received institutional funding from Premaitha Ltd. to aid the development of the IONA test. She is the Principal Investigator and is supporting recruitment to the IONA study at the Women's Centre in Oxford.Suggest a correction